Tractor



C. L. BEST TRACTOR Filed Jan. 12, 1921 s sheets-sheet 1 INVENTOR ATTORNE)- Dec.- 2 1924. 1,520,397

c. L. BEST TRACTOR Filed Jan. 12, 1921 3 Sheets-Shegt 2 IN V EN TOR A TQ EX- 0 gf arence ILBest C. L. BEST TRACTOR Filed'Jan. 12, 1921 3 Sheets-Sheet 3 IN VENTOR flarwwe L, 395$ A TTOR NE Y Patented Dec. 23, 1924.

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CLARENCE LEO BEST, OF SAN LEANDR-O, CALIFORNIA. ASSIGNOR 1'0 THE HOLT MANU- FACTURING COMPANY, OF STOCKTON, CALIFORNIA, A CORPORATION OF CALI- FORNIA.

TRACTOR.

Application filed January 1%,l921. Serial No. 438,643.

This invention relates to tractors which are essentially of the self-laying track type,

and the object of the invention is to produce a simple and compact structure which will be economical in construction and operation.

This'object I accomplish by using a single track laying unit which is arranged at one side of a main frame carrying a motor and transmission mechanism operatively connected thereto, and making use of a pair of ground wheels at the opposite side of the main frame forv steering the tractor and assisting in supportin and stabilizing the same. The round wheels are not traction wheels and they carry only a small portion of the weight. They are connected to the main frame by steering knuckles and are turnable simultaneously on their knuckles to cause the tractor to be steered.

One form which myfinvention may assume is exemplified in the"following description and illustrated in the accompanying drawings, in which Fig. 1 shows a plan view partly in section of a tractor embodying my invention,

gig. 2 shows a side elevation of the same, an I Fig. 3 shows a sectionalview in elevation taken through the rear axle of the tractor.

I show a track laying unit comprising a truck frame made up of parallel side bars 10 between which at the rear is journalled a driving sprocket wheel 11 and at the front an idler sprocket wheel 12. An endless chain track 13 operates over these sprocket wheels. Between the sprocket wheels the truckframe bows downwardly and receives a series of truck rollers l t which operate on the ground stretch of the track. On the inside truck frame bar I connect a main frame 15 which carries a motor 16 and a transmission mechanism -17. The rear sprocket wheel has an axle 18 which is operatively connected to the transmission mechanism by worm gearing 19. This axle extends entirely across the main frame beneath the latter and is connected by a universal joint 20 with a spindle '21 which carries a 'ground wheel- 2-2. The sprocket wheel 11 is fixed to the axle whereas the ground whee-l.v 1s turnable freely on the spindle which connects with theaxle. I The front sprocket wheel has an axle 23 also extending across the main frame and connected at its opposite end by means of a steering knuckle 2,4 to the spindle of a ground wheel 25.

Each wheel spindle carries a segmental toothed rack 26 meshing with a worm 27 on a longitudinally extending shaft 28. These worms 27 are pitched in opposite directions. The shaft 28 is journalled upon the main frame and carries a hand wheel 29 at its rear end within easy access of a drivers seat 30.

It will be seen that the tractor is driven entirely by the single track at one side and the bulk of the weight is carried by. this track unit sincethe ground wheels are spaced farther from the longitudinal center of the load. To steer the tractor the operator actuates the hand wheel 29 to cause the ground wheels to'be cramped so as to swing the track, I

laying unit in the desired direction. The steering connections. are such that when it-is desired to turn the tractor to the right the front. ground wheel will be turned inwardly at its forward portion and the rear ground wheel will be turned outwardly at its forward portion on account of the opposite pitch of the respective worms 27. A left turn of the tractor is accomplished by reversing the direction of the steering shaft.

The present tractor is extremely simple in construction and is quite small and compact and therefore is ideally suited for orchardwork and the like. Sufficient weightis im-' posed upon the single track laying unit to insure adequate traction, and b dispensing with a second track considerab e expense is saved in the matter of initial cost and upkeep.

Various changes in the construction and arrangement of the several parts herein shown and described may be employed with out departing from the spirit of my invention as disclosed in the appended claims.

.Having thus described my invention, what I claim and desire to secure by Letters Patent is 1. A tractor comprising a main frame, a track unit at one side thereof comprising a rear driving sprocket wheel, a front idler sprocket wheel, an endless flexible track enof the main frame and'a ground wheel jouraxles.

2. A tractor comprising a main frame,

nalled on the opposite end of each of said a track unit at one side thereof comprisinga rear drivin sprocket wheel,- & front'idler sprocket whee axles for said sprocket wheels extending transversely of the main frame,

a ground wheel journalledon the opposite end of each of said axles andja swivel connection between the spindle of each ground of the frame, an i wheel and the axle whereby to steer the tractor.

3. In a track-laying traotonthe combination of a single track-lazing unit, inclnding a frame, a drlving s roc etvwheel at the rear ler wheel at the. front of the frame, axles for said sprocket-and idler wheels, at power-supporting frame secured toone side of the track-laying frame,

and balancing and steering wheels arran ed at. the other side of the power-supporting frame and carried by said axles.

4. In a track-layin tractor, the combination of a single trac -laying vjiit, including a frame, a driving sprocket wheel 'at the rear of the frame, an idler wheel at the front of the-frame, axles for said sprocket and idler wheels, a power-suppql'ting frame secured to one side of the trash-laying frame, balancing andisteering Wheels arranged at the other side of the power-sup orting frame and carried'b said axles, an driving connections for t e axle, on which the sprocket wheel is mounted.

- CLARENCE LEOBEST. 

